Blocking ring release mechanism



'March 18, 1947. J, B POLQMSKl 2,417,566

BLOCKING RING` RELEASE MECHANISM March 1s, 1947. J, B, POLOMSK, 2,417,566

BLOCKING RING RELEASE MCHANISM Filed Feb. 1'7, 1944 2 Sheets-Shee-t 2 J5 .fzz/enzrf teeth 9 on the flange of the hub 8 that are engaged with internal teeth I on a shift collar II surrounding the hub flange. This arrangement permits said shift collar II to be rotated with the central hub 8, and it also allows the Vcollar to be slid on the hub flange in directions longitudinally of the axis of the load shaft. Blocker rings I2 and I3 having tapered inner faces I4 and I5, respectively, are positioned loosely upon the coacting synchronizer members that comprise tapered hubs I6 and IT on the respective gears 6 and '1. These blocker rings are provided with external blocker teeth I8 and I9 respectively that are adapted to be initially interposed in the path of movement of internal teeth I0 of the shift collar I I when the latter is slid in either direction towards the respective. gears 6 and 1, and which are rocked out of the path of teeth I0 when a relative reversalv of torque is effected between collar II and gear 6. The blocking function is brought about bythe usual lost motion connection between the rings and collar or hub which in the present embodiment takes the form of lugs 24'operating in recesses 25 in the hub and collar. During the cycle of operation of coupling the parts, if the shift collar is moved to the left in Fig. 1, the tapered faces I4 and I6 of blocker ring I2 and gear 6 will become frictionally engaged thereby rocking the ring into blocking positionand retaining it in this position until the relative direction of torque changes, whereupon the ring is rocked out of blocking position, and thereafter continued movement of shift collar II toward the left willcause its teeth I0 to slide through and beyond blocker teeth I8 and then mesh with annular clutch teeth 20 on the hu-b of gear 6 between the teeth of the latter' and its tapered hub surface I6. When the shift collar II is moved in theopposite direction from its central or neutral position its teeth I0 will initially engage blocker ring teeth I9, and after the tapered faces I5 and I 'I have become frictionaly engaged the continued movement of the shift collar to the right will mesh its teeth with the annular teeth 2I on the hub of gear 'I that are between the teeth of the latter and its tapered hub I1 in the manner shown in dotted lines in Fig. 1. In either of these extreme left or right positions of the shift collar I I the respective gear 6 or v1 will be coupled to the shaft 5 to effect transmission of torque from the one to the other of these coupled members. The initial movement of the rings is effected by means of a resilient ring 32 hereinafter to be described.

After thel synchronizing members have performed their function it is desirable that they be released so as to be in readiness to function again. It sometimes occurs that the frictional engagement between the tapered faces of the synchronizer members is so great that these faces have become firmly'locked together and upon torque reversal, roll past the unblocked position to a blocking position on the other side, thus preventing engagement of the coupling. Separation of the locked members becomes a difficult matter especially in transmission assemblies 4 wherein the release of these members is dependent upon the action of springs or other yieldable means that are not of a positive character. In the present instance, positive operating means are provided for effecting the release of the fricltionally engaged synchronizer members, such means being actuated preferably by the shift collar during its sliding movement with respect to the coacting elements of the transmission.

The releasing mechanism contemplated herein comprises a plurality of levers 22 on each ring and fulcrumed at their ends on pivots 23 in lugs 24 on the rings I2 and I3, the lugs being positionedv at the inner edges of said rings adjacent the junction between the flange and the connecting web of the central hub 8. These levers 22 are disposed longitudinally with respect to the axis of rotation of the coupling assembly, the ends opposite the fulcrums being disposed adjacent the respective positive clutch teeth 20 and 2| of the gears 6 and '1. The levers and their mounting,r lugs fit into the recesses 25 in the shift collar iI and hub member 8, and the ends of the levers ht into aligned recesses 26 in the blocker rings I2 and I3 between certain of their respective external teeth I8 and I9.

The outer ends of the levers 22 are formed with aproflle such as that shown in Fig. 1. Ilhe formed ends are adapted for'engagenient with cams which may comprise oblique or wedgeshaped annular surfaces 2'! formed on the gears 6 and I, said annular surfaces being adjacent the exterior clutch teeth 20 and 2| of the respective gears. Said annular cam surfaces 2'I oppose the ends of the levers 22 in such a manner that when said lever ends are moved in an inward radial direction. toward the axis of the assembly the cams will create pressure longitudinally of the levers 22 to forcibly move them away from the positive clutch teeth, and since the levers are anchored to the blocker rings I2 and I3, the respective ring that has been clutched will be bodily moved in a direction that will disengage the tapered clutch faces and release said blocker ring from its adjacent gear. The means that create the forces in an inward radial direction upon the operating ends of the levers 22 com prise annular cam members preferably in the form of oblique or wedge-shaped annular surfaces 28 on the under portion of the shift collar II adjacent the edges thereof, said annular cams 28 being adapted for engagement with laterally disposed outwardly extended lobes or enlargements29 on the adjacent portions of the levers 22.

When the shift collar II has been moved from neutral position toward one of the gears, for example to the left toward gear 6 (Fig. 1) and the synchronizing members of blocker ring I2 and said gear have been frictionally engaged and rotated to the unblocking position so as to start the collar II through the blocker teeth I8, the cam 28 at the left side of shift collar II will begin to depress the end of the adjacent lever 22, thus forcing it against the opposite cam 27 on gear 6. Continued sliding movement of the collar Il toward gear 6 will cause the cam 2'! to force the lever bodily in a direction opposite to the direction of movement of the collar and such bodily movement of the lever will release the blocker ring I2 from the tapered hub surface I6 or gear 6 by moving said blocker ring in a direction opposite to the Vdirection of movement of the shift collar. The released positions of the synchronizer clutch members and levers is illustrated .atf the right'inztFg. 1 in.` fullY linescandnthe extreme position of theshift collaryaftenthe releaseofa blocker ring and full engagement of the-couplingis shown in dotted lines in said gure aswell asithe `neutral position of the collar.

The cams that comprise the oblique or wedge surfaces 2l and Zlexertforces against the levers 22S in directions-or4 planes thatiare transverse to each other, andthe blocker ring that is frictionally clutched to its gear is bodily moved in an axial directionwhen beingreleased by the operation ofthe levers. In this arrangement positively operatingmeans are provided for eifecting disassociation of the synohronizer and the adjacent gear.v member ofthe transmission. Conceivably, the assembly which is.` herein shown in connectiony with a `coupling mechanism that includes two synchronizers of the blocker ring type may be effectively employed in an assembly wherein there is a single blocker ring and synchronizer.

When theshift-'collar II has been moved, for example/to the left (Fig. 1)' to activate blocker ring I2, the free or unpivoted outer endsof* the inactive release levers on the blo-cker ring'lz will have a tendency toswing in a radial direction outward beyond the adjacent edgev of the shift collar,- which is due tothe action of centrifugal force created by the rotation of the assembly. This tendency; however, is overcome in a definite and positive manner by providing oblique eccentricedges 22a upon the fulcrumed portions of said'levers in the manner shown in Fig. 1. Each of these edges 22al is adapted to engage stop por tion 2219 at theinner end of the `slot 24a that is between the pair ofmounting lugs 2.4for the respective levers.

The aforementioned blocker ring energizing means comprises oppositely extended cam faces SIIinshift-collar Il that form a flat V-shaped recess on the inside ofthe collar asshown in Fig. l, and there is an annular channel( 3I` in the hub opposite these cam faces. A split expanding spring 32 of proper diameter is positioned 'in the hub channel SI, and it is so located that it will beengaged by a cam face 30when theshift collar moves' out of neutral position. The movement ofthe shift collar II forces the ring into engage-` ment with the `lugs 24 of the adjacent blocker ring, which in turn is pushed in a direction axial of the' assembly to` engage theA tapered friction clutch faces of the synchrcnizer with each other, in the manner shown at the left in Fig. 1.

Thus the force which is exerted by the transmission shift lever in shifting the collar out of neutral is utilized in a direct and positive manner not only to engage the'synchronizer clutch members, but such direct force is also employed to operateu the positive means for releasing the synchronizer blocker ring from its frictional engagement with the gear that is being coupled with or to the shaft 5L When the shift collar -I I isjin its intermediate or inactive neutral position, the blocker rings I2 and I3 are maintained with their teeth I8 and I9 respectively normally in blocking positions re1- ative to the internal teeth IIl on the shift collar'k to prevent a forced or crash shift. This blocking relationship is maintained by suitable instrumentalities that are located circumferentially` intermediate the blocker release levers 22 and comprise abutment lugs 33 that tinto recessesr3'in the shift collar I I and the hub member 8. These abutment lugs are located preferably midway between the recesses 25 that accommodatethe release lever mounting lugs 24. Elastic: members'su'chi as coiled. springs '35. are inter@ posed betweenitheabutment lugs 33 and the ad.-

vjacent transversefas ofythe recesses.34.` The ends of each spring, are inserted into a seat36 formed in the transverse. face. `of the respective abutnientlug 33 andv press against the confrontE ing` transverse face 3l' of the recess 34. Thus, whenv the shift collaris'being moved toward the left` (Fig. 1) the blocker ring. I2l and gear- 6 Will become gradually engaged, and when the gear begins to rotate more slowly than the ring, .the latter will rotate in an unblocking direction.V to permit Vthe shift collar to mesh its teeth I3 with the blocker ring teeth that have become aligned therewith as the ring moves out of blocking position.v The compression of the springs under these conditions during. the shifting and aligning `op eration will allow the ring l2 to move out cf `its blocking position and the meshing of the teeth lil and. ill will be readily'consummated in a noiseless manner and without a clashing thereof.

Figs; 5 to 8 inclusive graphically illustrate the cycle of operating the blocker and release mechanism. Fig. 5 shows the relative positions of the parts when the assembly is at neutral, whereinthe tapered or conical inner face til of blocker ring vI2 is out of frictional. Contact with the tapered hub I on gear 3. ln` this position, internal teeth I3 on'shift collar il are out of engagement With blocker ring teeth I8.

When shift collar ii moves toward 'blocker I8 (Fig. 6) the blocker ring energizing means begins to operate by reason of the cam face 33 in collar teeth I El moving the split spring 32A in the hub channel 3|, thus forcing said spring against blocker `ring lugs 24` and 33 thereby moving blc-cker ring I2 into frictional engagement with the cone face of gear hub It; Atthis stage gear 6 begins to rotate at. a. speed approaching that of blocker ring I2fand` the enlarged end -29'-of lever 22has moved radially outward on cam face 27 of gear t where it is in the path of the chamfered or undercut cam 28 on shift collar il. Fig. 6 shows this position of the parts.

Asthe movement of shift collar Il progresses to the position` shown in .Fig '2, collar teeth IQ slide into blocker teeth i3 until meshed therewith and while doing so the-collar cam 28, acting on the end of lever 22., vexerts pressure radially inward thereon so that the end of lever 22 is then moved down or radially inward on gear cam 211 and a longitudinal force is exerted on said lever. Since lever 22 is fulcrumed on blocker ring I 2, this longitudinal force on the lever is transmitted directly to blocker ring l2 so that said blocker ring is shifted away from gear 5 or axially of the assemby to effecty a positive breakaway of blocker ring i2 fromgear hub IG. During this breakaway the spring 32 has been pushed by the blocker ring toward the opposite side of channel 3I where it will remanuntil shift collar II is returned to neutral.

\ The shift collar, as shown in Fig. 8, continues its movement to the left until its teeth I0 haveentered through the teeth 2! on gear. It will be seen that this backing off or breakaway of blocker ring I2 from gear '3 is approximately at the time of or preferably just prior to the meshing of shift collar teeth Iii with teeth 26 on gear 6.

Springs 35 function to maintain the blocking teeth I8 in blocking position until there is a reversal of torque, whereupon said springs are compressed and the blocking teeth aremoved out of blocking position to permit collar, teeth I0 to pass therethrough into engagement with gear teeth 2i);

At the same time there is a breaking away of the blocker ring from the tapered hub of gear 6.

While this invention has been described in detail in its present preferred form or embodiment, it will be apparent to persons skilled in the art, after understanding the improvements contemplated herein, that various changes and modifications may be made therein without departing from the spirit and scope thereof. It is aimed in the appended claims to cover all such changes and modifications.

I claim:

1. A power transmitting coupling comprising a rotatable element; another element adapted for connection to the rotatable element; synchronizing means between said elements to prevent engagement thereof except upon substantial synchronization of said elements, said synchronizing means comprising an axially xed friction member and a friction member movable axially into engagement with the fixed member, the fixed member being operable with one of the said coupling elements; a slidable clutch collar drivingly associated with the other of said elements and adapted to establish a positive connection between the elements; means operated by the collar prior to the establishment of the positive connection to operate the synchronizing means; and means also operated by the collar prior to the establishment of the positive connection but subsequent to the operation of the synchronizing means to transmit force applied to the collar directly to the movable friction member of the synchroniz-` ing means to force the movable friction member away from the fixed friction member.

2. A power transmitting coupling as defined in claim 1, wherein one of the friction members has means projecting into the path of movement of the collar to block engagement thereof.

3. A power transmitting coupling comprising a driving element, and a driven element adapted for connection thereto; friction means interposed between said elements adapted to synchronize the rotation of said elements; a positive clutch interposed between said elements, said positive clutch including a sliding clutch collar driven by said driving element and adapted to establish positive driving connection between said elements, said collar during its sliding movement adapted to operate said friction means to establish the aforesaid synchronized rotation of said elements prior to the establishment of said positive connection therebetween; and means actuated by said collar for transmitting force applied to said collar directly to the friction means to disconnectl the latter prior to the operation of said positive clutch.

4. A power transmitting coupling comprising a rotatable shaft; a gear loose on said shaft adapted for connection thereto; a friction synchronizer interposed between said shaft and gear including cooperating axially xed and axially movable members, the fixed member being carried by said gear; a slidable shift collar rotated by said shaft and adapted to engage the movable synchronizer member with said fixed member; cams on said gear and said collar; and means on the movable synchronizer member engaged by said cams for forcibly releasing the members of the synchronizer.

5. A power transmitting coupling as defined in claim 4, wherein the means for releasing the movable synchronizer member comprise levers v fulcrumed on said movable member and disposed with their free ends in position to be contacted by said cams.

6. A power transmitting coupling comprising a rotatable shaft; a gear loose on said shaft adapted for connection thereto; a synchronizer interposed between said shaft and gear, said synchronizer including blocking means for preventing operation of the coupling until substantial synchronization of the parts thereof has been achieved, and a shift collar for energizing said blocking means to establish synchronization between said shaft and gear; and means for deenergizing said blocking means comprising oscillatory means carried by the blocking means; and cam means on said shift collar and said gear for moving said oscillatory means in a direction to disengage the blocker ring from the opposing clutch member.

7. A power transmitting coupling as defined in claim 6, wherein the oscillatory means comprise levers fulcrumed on the blocker ring, and the cam means comprise oblique annular faces on proximate portions of the shift collar and the gear.

8. A power transmitting coupling comprising a'rotatable shaft; a gear loose on said shaft adapted for connection thereto; synchronizer means interposed between said shaft and gear, and including axially fixed and axially movable friction members, one member being carried by said gear and the other member being normally inactive; a shift collar rotatable with said shaft adapted to move the normally inactive member into frictional engagement with the member on said gear; cams on said gear and said collar; and means on said normally inactive member engaged with said cams when said collar has shifted a predetermined distance to effect a positive connection between the collar and the normally inactive member, the further movement of said vcollar adapted to operate said means to bodily move the clutch member out of engagement with its opposing member on the gear. l

9. A power transmitting coupling as defined in claim 8, wherein the means on the normally inactive member comprise levers fulcrumed on said member and disposed with their movable portions in positions to be engaged by the cams on the gear and collar.

10. A power transmitting coupling comprising a rotatable shaft; spaced gears loose on said shaft adapted for selective connection thereto; a fianged hub xed to said shaft and rotatable therewith between said gears; synchronizing friction clutches cooperating with the respective gears; a shift collar carried by said hub flange and rotatable therewith, said shift collar adapted to selectively actuate said clutches and effect connection between a gear and said shaft means on the movable members of each clutch that are adapted to release each member from its opposing clutch member; and cams on said gears and the proximate portions of said collar adapted to engage the aforesaid means to effect release of the respective clutch member.

11. A power transmitting coupling as defined in claim 10, wherein the means on the movable clutch members comprise levers fulcrumed on said clutch members and disposed with their movable end portions between the respective cams on the collar and gear.

12. In a synchronizing coupling device, a toothed driving member; a toothed driven member aligned with the driving member; an internally splined collar slidable on one of said mem- 9 bers adapted' to Y connect the 'two membersv` in driving relation; a toothed blocking means in terposed between the ldriving `and driven l members; means for 'drivinglsaid blocking means from one kof said members; alost-motion connection between the "blockinglmeans 'and the 'said one member comprising a lug and recess; resilient means biasing the lug `in one direction in its recess so as tolposition the blocking `means to block the movement of the collar to engaged position; a cone `frictionclutch between the blocking means `andthe driving member whereby to synchronize rotation of the driving and driven members prior to the 'establishment of a positive connection therebetween by said collar; and cam meansA operated by said collar in its movement toward engaged position for forcibly and positively disconnecting-the friction clutch.

13. A 'synchronizing coupling device as defined in claim 12, wherein the `lug in the lost-motion connection is 'on' the :blocking means and the recess that cooperates Vwith the lug is in the said one member, `and the resilient means comprises a spring interposedbetween the lug and a wall of the recess and exerts its pressure circumferentially of the'blocking means.`

14. In a synchronizing coupling device, a toothed driving member; a toothed driven member aligned with the driving member; an internally splined collar slidable on the driven member adapted to connectthe two members in driving relation; a toothed'blocker ring on the driven member; means for driving said blocker ring from' the driven member; a lost-motionconnection between the blocker ring Aand the driven member comprising a `recessl in the driven member and a lug on said blocker ring projecting into said recess; a coiled spring interposed between the lug and` a confronting wall of the recess for biasing the lug in one direction in its recess so as to positiontthe blocker ring to block the movement of the collar to engaged position; a cone friction clutch between the-blocker ring and the driving member whereby to synchronize rotation of the driving and driven members prior to the establishmentv of a `positive connection therebetween by said-collar; and lcam means operated by said `collar-in its movement 'toward engaged position for forcibly and positively disconnecting the friction clutch.

15. In a synchronizing coupling device, a

toothed driving member; a toothed driven memv ber aligned with the driving member; an internally splined collar slidable on the driven member adapted to connect the two members in driving relation; a toothed blocker ring on the driven member; means for driving said blocker ring from the driven member; means for biasing the blocker ring in one direction of its movement so as to position the blocker ring to block the movement of the collar to engaged position; a cone friction clutch between the blocker ring and the driving member whereby to synchronize rotation of the driving and driven members prior to the establishment of a positive connection therebetween by said collar; levers each fulcrumed at one end on said blocker ring; and cams on said collar and said driving member for engaging the free ends of said levers during movement of said collar toward its engaged position for forcibly and positively disconnecting the friction clutch.

16. In a synchronizing coupling device, a toothed driving member; a toothed driven member aligned with the driving member; an lnagitato ternally Asplined collar slidable on'one of said members andladaptedlto connect the two membersin drivingrelation; a'toothedblocking member located betweenfthe 'driving and driven mem.' berasaid -blocking -member normally occupying an yangular positionlinfwhieh it prevents movement or said collar to connect the driving and drivenmembers vbut"beingmovable to a second angular l position to permit t'su'ch connection; means "for `normally .holding said blocking member`in said first mentioned angular position: means on said driving member and Asaid blocking member" derlning'a friction "clutch adapted to drivngly connect said members; means actuated by said collar for effecting clutch engagement to thereby move said blocking member to its un-` blocked position andsynchronize rotation of the driving and drivenmembers prior to theA movement of'said collar to establish a positive connection between the driving and driven members; and meansdriven by 'said collar in its movement to establish such a connection 'for positively moving said blocking member "in an axial direction to disconnectsaid clutch and in so doing moving the blockingmember to an axial position in which it may return freely to its normal blockingpositi'on when said collar is operated to disestablish thepositive connection between the driving and driven members.

17. In a synchronizing coupling device, a toothed driving member; a toothed drivenmember aligned with the driving member; an internally splined collarslidable 'on one of said members and adapted to connect the two members in drivingrelati'on; a toothed blocking member located between the driving and driven members, said blo-cking 4member normally occupying an angular position in which it prevents movement of said collar'to yconnect the driving and driven members but being movable to a second angular position to permit suchconnection; means for normally holding said blocking member in said rst'mentioned angular position; a

friction clutch, one friction surface of said clutch being on said driving member and thecooperating friction surface being on said blocking member; means actuated by'said collar for engaging said clutch to thereby move saidblocking member to its unblockedpositionfand synchronize rotation of thedriving and driven members prior to the movement of said collar to establish a positive connection between the driving and driven members; and means driven by said collar in its movement to establish such a connection for positively moving said blocking member in an axial direction to disconnect said clutch and in so doing moving the blocking member to an axial position in which it may return freely to its normal blocking position when said collar is operated to disestablish the positive connection between the driving and driven members.

i8. A power transmitting coupling comprising a rotatable driving member; a rotatable driven member coaxial to said driving member and adapted to be drivingly connected thereto; fixed and movable fricticnally engageable means adapted to synchronize rotation of said driving and driven members; an axially shiftable collar adapted to effect engagement of said movable friction means with said rlxed friction means; longitudinally arranged lever means fulcrumed on said movable friction means; and means defining a first cam and other means defining a second cam, said first cam being arranged to be effective during shifting of said collar to move a portion of said lever means into engagement with said second cam, and said second cam being arranged to be effective during further shifting of said collar to urge the said portion of the lever means against said first cam means to forcibly release said frictionally engageable synchronizing means.

19. A power transmitting coupling as defined in claim 18 wherein the fir-st and second cams are spaced axially apart and one of said cams is adapted to be bodily moved toward the other cam during the shifting of the collar.

20. A power transmitting coupling comprising a rotatable driving gear; a rotatable driven member coaxial to said driving gear and adapted to be drivingly connected thereto; means on said driving gear and said driven member dening a friction clutch adapted to synchronize rotation of said gear and member; an axially sliiftable collar adapted to effect engagement of said friction clutch; longitudinally arranged lever means fulcrumed on the movable member of said friction clutch; means defining a rst cam; and means defining a second cam, said first cam being arranged to be effective during shifting of said collar to move a, portion of said lever means into engagement with said second cam, and said second cam being arranged to be effective during further shifting of said collar to urge the said portion of the lever means against said r-st cam means to forcibly release said friction clutch.

2l. A power transmitting coupling comprising a rotatable driving gear; a rotatable driven member coaxial to said driving gear and adapted to be drivingly connected thereto; a clutch assembly including a friction surface rotatable with said driving gear, and a movable friction member rotatable with said driven member, said clutch assembly being adapted to synchronize rotation of said driving gear and driven member; an axially shiftable collar cooperating with said movable clutch friction member and adapted to effect engagement of said friction clutch; longitudinally arranged lever means fulcrumed on said movable clutch member; means defining a first cam associated with said driving gear; andwmeans on said collar defining a second cam, said rst cam being arranged to be effective during shifting of said collar to move a portion of said lever means into engagement with said second cam,

12 and lsaid second cam being arranged to be effective during further shifting of said collar to urge the said portion of the lever means against said first cam means to forcibly release said clutch.

22. A power transmitting coupling comprising driving and driven members; a positive clutch member .adapted for axial movement to effect connection of said driving and driven members; a friction clutch member adapted for axial movement to effect synchronized driving relation between said driving and driven members prior to connection of said members by said positive clutch member; and means adapted to release said friction clutch member subsequent to initial engagement of said driving and driven members, said means comprising lever members fulcrumed o n said friction clutch member,` and cam means carried by said driving member and driven membei-.for operating said lever members to bodily retract said friction clutch member thereby to effect the aforesaid release thereof.

23. A power transmitting coupling comprising driving and driven members; a positive Clutch member adapted for axial movement to effect connection of said driving and driven members; a friction clutch member adapted for axial movement to effect synchronized driving relation between said driving and driven members prior to connection of said members by said positive clutch member; lever members fulcrumed on said friction clutch member; and spaced cam means carried respectively by said driving and driven members, one of said cam means being arranged to be moved bodily towards the other cam means whereby to act on said lever members to produce a positive force thereon to release said friction clutch member.

JOHN B. POLOMSKI.

REFERENCES CITED The following references are of record in the iile of this patent:

UNITED STATES PATENTS Christman Mar. 14, 1933 

